A component of his Confidence interval study involves Hazard ratio and Relative risk. Internal medicine and Multivariate analysis are commonly linked in his work. He regularly links together related areas like Internal medicine in his Multivariate analysis studies. Michael F. Leitzmann undertakes interdisciplinary study in the fields of Prospective cohort study and Retrospective cohort study through his works. His multidisciplinary approach integrates Retrospective cohort study and Relative risk in his work. He combines Cohort and Cohort study in his studies. He incorporates Cohort study and Cohort in his studies. He performs integrative study on Body mass index and Waist. He combines Waist and Waist–hip ratio in his research.